Nerve agents protective equipment

Brief but informative site on sarin nerve agent. Describes sarin, its history as a terrorist agent, protective equipment, and dosage effects. Nice bibliography and links to other sites with reference documents on sarin. 

Occupational Safety and Health Administration, National Institute for Occupational Safety and Health. Interim Guidance on Personal Protective Equipment Selection for Emergency Responders Nerve Agents, August 30, 2004 (http //www.osha.gov/SLTC/... 

Personal Protective Equipment Standard turnout gear with SCBA provides a first responder with sufficient protection from nerve agent vapor hazards inside interior or downwind areas of the hot zone to allow thirty minutes rescue time for known live victims. Self-taped turnout gear with SCBA provides sufficient protection in an unknown nerve agent environment for a three-minute reconnaissance to search for living victims, (or a two-minute reconnaissance if mustard, blister agent (HD) is suspected). 

Personal Protective Equipment Standard turnout gear with SCBA provides a first responder with sufficient protection from nerve agent vapor hazards inside interior or downwind areas of the hot zone to allow thirty minutes rescue time for known live victims. 

These enzymes are promising for destruction of chemical weapons stockpiles, soil remediation, decontamination of materials, protective equipment, and water polluted by pesticides and nerve agents (Russel et al, 2003). In particular, phosphorothiolates such as VX are relatively resistant to PTE. Thus, oxidative cleavage of the P-S bond could be achieved by oxidases like laccases. These enzymes could be used in association with other OP-degrading enzymes for skin decontamination or in topical skin protection formulations. Though no work has been performed on combined action of oxidases and hydrolases, oxidation of P-bonded alkyl/aryl chains by oxidases is expected to alter enantio-selectivity of PTE for parent OPs, and therefore to improve the efficiency of catalytic bioscavengers. 

During WWII, extensive testing of HD was undertaken (by the U.S. Army) for the purpose of evaluating the effectiveness of decontamination and protective equipment. Volunteers in such tests were found to have increased posttraumatic stress disorder (PTSD 17% prevalence and 33% subdiagnostic PTSD prevalence) when evaluated 50 years later (Schnurr et al., 1996). The number of exposures to the gas was predictive of lifetime PTSD. No acute exposures to HD or immediate problems were reported. McDonough and Romano, in Chapter 4 of this book, discuss reports of the human volunteer experiments done in the United Kingdom over a 50 year period. They reported that there was no evidence that exposure of volunteers to low doses of nerve agents resulted in any adverse medical sequelae, to include psychiatric symptoms. 

There are important differences between on-target military attacks against relatively well-protected armed forces and nerve agent attacks initiated by terrorists against a civilian population. In contrast to military personnel, civilians are unlikely to be pre-treated with pyridostigmine and protected by personal protective equipment (PPE). Furthermore, the time after exposure when specific therapy can first be administered to civilians is likely to be delayed. Even conservative estimates suggest a delay between exposure and the first administration of atropine/oxime of at least 30 min. The clinical importance of this delay is discussed below. 

Nerve Agents- Decontamination of patients. The importance of early decontamination can not be over emphasized. Decontamination of the skin should be accomplished quickly if it is to be fully effective. Liquid agent may be removed by fullers earth or chemically inactivated by the use of reactive decontaminants. Decontamination personnel should wear a mask and protective equipment while decontamination is performed. Once a casualty has been decontaminated, or the agent fully removed, no further risk of contamination exists. The casualty s body fluids, urine, or feces do not present a chemical warfare (CW) hazard. 

Fig. 2-37. The M5 Combat Service Mask, the first U.S. mask with the canister placed directly on the cheek. The M5 mask was part of the personal equipment of the troops who landed at Normandy on 6 June 1944. Postwar tests indicated that it might have protected against respiratory exposure to the nerve agent tabun if the Germans had chosen to use it against the invasion armada. Photograph Chemical and Biological Defense Command Historical Research and Response Team, Aberdeen Proving Ground, Md.

After World War II, as western defense became increasingly based on the threatened use of nuclear weapons, the Chemical Corps s mission expanded to include radiological protection as well as chemical and biological research and development. At the same time, the Corps concentrated on producing and fielding nerve agent weapons and the assorted detection and decontamination equipment required. 

The most common agents in modern arsenals are vesicants and nerve agents. Cyanides and pulmonary toxicants are thought to be represented in some stockpiles, but are typically less toxic and more difficult to employ because of their physical characteristics. Some cyanides and pulmonary toxicants have specific characteristics that make them appropriate for military use, such as rapid rate of action, very low persistency, and the ability to penetrate or damage protective equipment. 

To minimize such problems, continuous training is required so that soldiers are comfortable donning their protective equipment and operating in a chemically contaminated environment. Similarly, soldiers must understand the rationale for taking the nerve agent pretreatment, pyridostigmine, as an... 

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